QuakeScout
Magnitude3.7

Reviewed by USGS22y ago

M3.7 earthquake in Fiji region

Sunday, September 5, 2004, 17:26:44 UTC · 19.531°S, 177.655°W

A magnitude 3.7 earthquake struck in Fiji region on Sunday, September 5, 2004, 17:26:44 UTC, at a depth of 262.8 km (intermediate).

Magnitude
3.7
Minor · mb
Depth
263 km
Intermediate
Felt reports
0
Did You Feel It?
Est. shaking
—
No ShakeMap
PAGER alert
None
Not issued
Tsunami
No flag
USGS feed

Outlined circle: this earthquakeDashed circle: 50 km aftershock search area

In context

How big was it, and why here?

Energy released

5 tons of TNT

That is about 1/2,814 of the Hiroshima bomb. A magnitude 5.0 releases about 89 times more energy.

Tectonic setting

121 km

from the nearest mapped plate boundary, between the Niuafo'ou and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: intermediate

263 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

Did You Feel It?

Where it was felt

No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.

I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.

After the main event

Aftershocks within 50 km

USGS lists 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.6 on September 21, 2004. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

M3M41h6h1d3d7d14d30dMainshock M3.7
Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.
  1. 4.6279 km WNW of Haveluloto, Tonga22y ago · 36 km SE of this epicenter
  2. 4.5Fiji region22y ago · 50 km N of this epicenter
  3. 4.2Fiji region22y ago · 38 km N of this epicenter

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,389 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

  1. 8.0TongaJanuary 4, 1903 · 283 km E of this epicenter
  2. 7.8159 km W of Pangai, TongaDecember 14, 1950 · 188 km E of this epicenter
  3. 7.8Fiji regionJanuary 1, 1919 · 50 km NW of this epicenter
  4. 7.8192 km WSW of Haveluloto, TongaOctober 14, 1997 · 300 km S of this epicenter
  5. 7.6178 km E of Levuka, FijiFebruary 22, 1909 · 205 km NW of this epicenter
  6. 7.6240 km E of Levuka, FijiMarch 9, 1994 · 184 km NW of this epicenter
  7. 7.5262 km WNW of Haveluloto, TongaMay 21, 1962 · 65 km S of this epicenter
  8. 7.4227 km E of Levuka, FijiAugust 21, 1910 · 213 km NW of this epicenter

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 9 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1937M8.1

    Fiji Islands

    16 Apr 1937 · 229 km away

  2. 1903M8.0

    Tonga Islands

    4 Jan 1903 · 283 km away

  3. 1909M7.8

    Fiji Islands

    22 Feb 1909 · 221 km away

  4. 1919M7.8

    Fiji Islands

    1 Jan 1919 · 50 km away

    tsunami

  5. 1950M7.7

    Tonga Islands

    14 Dec 1950 · 173 km away · intensity VI

  6. 1997M7.7

    Tonga Islands

    14 Oct 1997 · 300 km away

    tsunami

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers

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